The John Hancock Tower is an office building commissioned by the John Hancock Mutual Life Insurance Company principally for its own use, with a few floors occupied by other tenants. The building contains a gross floor area of 2,060,000 square feet on sixty-two floors above grade
and two below. It is located at 200 Clarendon Street, adjacent to Trinity Church and Copley Square, in Boston, Massachusetts. The architect was I. M. Pei & Partners (now Pei Cobb Freed & Partners), with Henry N. Cobb, FAIA, as design partner, Eason H. Leonard, FAIA, as administrative partner, Werner Wandelmeier, FAIA, as project manager, Michael D. Flynn, FAIA, as project architect for curtain wall, Harold Fredenburgh, AIA, as project design architect, Michael Vissichelli, AIA, as Job
Captain, and Andrej Gorczynski, AIA, and Patrick Lestingi, AIA, as staff architects. Construction was completed in 1976.

The John Hancock Tower recently achieved LEED Gold Existing Building certification for energy use, lighting, water, and material use as well as a variety of other sustainable strategies. Some of these involve equipment upgrades, while others were integral to the original design. For example, the building's glass façade and narrow floor plate allow natural light to
reach 86 percent of all work areas.

In a lecture delivered at the Harvard Graduate School of Design in 1980, Cobb explained the design of the Hancock Tower as follows.

The extreme disparity in size between the tower and the church was the central predicament we faced. We chose to deal with it not by creating a gratuitous distance between the two—this would only have exacerbated the problem—but by bringing them into close proximity while positioning and shaping the tower in
such a way that the church becomes the autonomous center and the tower the contingent satellite in the composition. To accomplish this, several aspects of the tower's design may be cited as essential: First, the attenuated rhomboid plan-form emphasizes the planar and minimizes the volumetric presences of the building. Second, placement of the rhomboid diagonally on the site, with its narrow edge adjacent to the church, effectively disembodies the tower as seen from the square. Third, notches
bisecting the end walls accentuate the weightless verticality of these planes and make legible the tower's nonrectangular geometry. Fourth, the triangular space created between the church and the broad face of the tower pays homage to the apsidal view of Richardson's building, reinforcing its intended role as the architectural cynosure of Copley Square. Fifth, the tower's uniformly gridded and reflective surface, stripped of all elements that might suggest a third dimension, mutes the
obtrusiveness of its enormous bulk and defers in all respects to the rich sculptural qualities of its much smaller neighbor. With regard to this latter aspect, it should especially be noted that the three-story-high lobby at the base of the tower is sheathed in the same manner as all other floors; had the monumental scale of this space been directly expressed or exposed to view from the outside, it surely would have upset the delicate balance in the dialogue between church and tower.

As the foregoing suggests, we adopted a strategy of minimalism in the design of the Hancock Tower not for ideological reasons, but because the situation
of the building demanded it. In the determined pursuit of our goal—to achieve a symbiosis between the church, the tower, and the square—we excluded everything that did not contribute directly to this end. For we believed that only thus could we temper the inherent arrogance of so large a building and endow it with a presence that might animate rather than oppress the urban scene.